Insulator-clamp.



E G. HATC INSULATO APPUCATION FILE 1,210,470. Patented Jan. 2, 1917.

- 3 SHEET$-SHET I.

E G. HATCH.

INSULATOR CLAMP.

APPLICATION mm 11m. 19, 19:5.

Patented Jan. 2, 1917.

3 SHEETS-SHEET 2.

E G. HATCH.

INSULATOR CLAMP.

APPLICAHON man um. 19. I915.

1,210,470. Patented Jan. 2, 1917.

3 SHEETS-SHEET 3.

UNITED sTATEsrA'rENT OFFICE.

EDWIN G. HATCH, OF'HOBVOKEN, NEW JERSEY.

' INSULATOR-CLAMP.

This invention relates to insulator clamps for clamping'a conductor to an insulator, but more particularly to that general type of insulator clamp in which the conductor is supported ontop of the insulator and the clampingimeans or members embrace orv encircle the body of the insulator.

In the past, accidents have occurred, in which property has often been damaged and people have sometimes "been killed, where electric wires have broken'on high tension line-crossings over railroad right of way or over telephone, and telegraph lines. It is very desirable and in fact highlyimportant, th'e refore,to make certain that high tension electric wires, especially at the crossings, are fastened to the insulators which carry the wires, just as efiiciently as possible. A double. cross, arm construction has been found to be highly efficient, and by this construction I mean the' case in which several insulators are used instead o'fone, each in- I sulator being supportedonits owncross arm of, wood or steel, and clamping means being provided'for fastening the conductor to both insulators. The advantage of this double cross arm construction resides inlthe fact that should one insulator'fail, the line will notfall down against the cross arm and be grounded, producing'a bad short circuit condition; It is unlikely that all insulators would fail at the same time and at any rate,

. a'factorof safety, which isrequired, is by this means provided.

(One of the objects of this invention is to produce a simple, yet a highly efficient means of attaching the electric line or conductor to the several insulators. Devices to accomplish this object have been designed in the; past-1 and used to considerable extent. There are two' general types of insulator clamp, the first embodying a cap generally of iron as a part'of the construction, which cap is cementedjto the insulator head and the second type embodying insulator clamps which encircle the neck of the insulator, and aresecu'red thereto and provided with conductor,, gripping devices for directly hold- Specificatfon of Letters Patent.

Application filed January 19, 1915. i Serial No. 3,030.

ing the, conductor. One of the objections to the first type of clamp has been found from experience to be that the iron caps very often work loose because of the difference between the coefficients of expansion of metal and porcelain, so that extremes of temperature, as a rule, result in a cracking of the porcelain or cement, thus eventually loosening the cap and decreasing the chiciency of the device. Certain other objections have been found to insulator clamps in general, which apply as well to the second type of clamp. Theseclamps are made of metal and although they may be so de-' signed that they will not clamp the insulator tightly, it is a fact that in practice they do clamp the insulator very tightly in many instances, because there is considerable variation in the sizes of insulators, even of the same'make and style. The reason for this is that insulators are made from molds and when the mold is new, an insulator of one size will be produced, but when the mold is old, a variation in the dimensions of the insulator will be apparent. The clamp should be designed for an average size of insulator, but the porcelain of which the insulators are made is very brittle and easily chipped, so that when the clamps do not come in contact uniformly with the porcelain, strain is produced at certain points, which may cause cracking or chipping of the insulator, thus reducing its efficiency very materially, if not entirely ruining the insulator. To meet these objections, I have designed a clamping set which aims at eliminating the strains on the insulator, first by reducing the amount of metal surface in contact with the insulator, and secondly, by the introduction of an elastic or plastic material forming cushioning means between the metal member and the porcelain. I This material may be of some elastic substance, like rubber, or a more or less plastic material, as lead, which will readily adjust itself to variations in the contour of the insulator.

In different insulators, a variation often exists in the dimension or distance between the center line of the side groove which holds the clamps, and the bottom of the top groove of the insulator which holds the conductor, and to provide for this difference, I have designed an adjustable clamping arrangement in. which suitable provision is fore constructed, it is not always possible to i ing members, so that allowance can be made for the variations referred to without straining the conductor. My improved insulator clamp can also be so adjusted that the conductor will be certain to rest on the top of the insulator which is meant to carry the weight. In an ordinary clamp, as heretoinsure that the conductor will rest on the top of the insulator, because the clamp must be made large enough to accommodate the maximum dimension between the bottom of the top groove and the center line of the side groove. If the clamp were to be made smaller than this, the conductor would be pulled down into the clamping members, which would strain the line and produce a kink or bend in it, thus weakening the line. If, on the other hand, the clamping members carry the conductor too high, the weight of the conductor would not come on the insulator head and might cause damage by bending the clamps down and injuring the poroelain.

In accordance with my improvement, provision is also made for an adustment in the dimension between the center lines or axes of the several insulators forming the clampin set, and in order to provide for this adjustment, I tie the clamps of the insulators together, as by means of adjustable tie rods or turn buckles or other suitable devices. The use of such adjustable tie rods enables the separate clamping members to be tightly bound together and I also provide suitable means for bracing the tie rods, so that the clamping set is restrained from twisting sidewise and will keep its shape and alinement.

Insulator clamps, as a rule, and sometimes cemented .caps, have clamping members de signed to fit only one size of conductor. I have provided means, however, whereby the clamping members will engage several different sizes of conductor without requiring a special design or part. In order to effect this result, I employ bushings or sleeves preferably of thin sheet metal, which are wrapped around the conductor at the insulator heads, as well as between the jaws of the clamps. The use of these bushings is not absolutely essential, although they protect the conductor from any possible abrasion and serve the further purpose at the insulators of protecting the line from any slight leaks whichmay occur through the insulator heads.

My construction of clamping set also serves to act as an arcing shield to protect the conductor on flash over. The conductor gripping devices may extend for a substantial distance beyond the insulators, if desired, and these features of construction are fully described hereafter.

Preferred means for carrying out the invention are shown in the acompanying drawmgs, 1n wh1ch Figure 1 is a side elevation of a clamping set; Fig. 2 is a plan view partly in horizontal section and partly broken away; Fig. 3 is a side elevation of a modification; Fig. at is a plan view of Fig. 3 partly in horizontal section and partly broken away; Fig. 5 is a plan view of another modification partly in section and partly broken away; Fig. 6 is a detail transverse sectional view on the line 66 of Fig. 1 and Fig. 7 is a detail side elevation of an insulator partly broken away showing a modified form of clamp.

Referring to the drawings, A and B represent two insulators mounted on the cross arms C and D which are connected in the usual manner by the cross piece E. In the form of the invention shown in Figs. 1 and 2, the insulator clamps for each insulator are constructed alike, so that a description of one applies to the other. Each insulator is provided with a clamp, comprising the clamping member F and a suitable conductor gripping device comprising the members G and H. The conductor J is supported in the grooves K in the top of the insulators and the clamping members F embrace the insulators in the circumferential grooves L.

In the form of the invent-ion shown in Figs. 1 and 2, the clamping members F are shown substantially in the form of semi-circles and only partially encircle the insulators. Between each clamping member F and the insulator is preferably provided a cushioning means 0 of elastic material or soft metal. As shown in this instance the clamping member F is provided with the lugs P and the gripping member G is pivoted on the bolt Q. The gripping member or jaw H is suitably secured to the member G as by means of the bolts R. The clamping members F are suitably tied together as by means of the tie rods S which may be provided with the screw threaded ends T engaging the lugs U on the clamping members, so that the tie rods may be adjusted and tightened as by means of the nuts V. In order to brace the clamping set transversely and keep it in alinement, projections IV may be provided on the clampingmembers F bearing against the tie rods S, so that a rigid construction is afforded.

In order to provide for variations in height in different insulators between the bottom of the top groove K and the center line of the side groove L, I prefer to provide means for vertical adjustment of the bolt Q, in the lugs P and a simple mode of conductor J is shown in detail in Fig. 6 as a split sleeve preferably of soft metal, which may be wrapped around the conductor and in this way conductors of different sizes may be accommodated by the clamp. If the sleeve Y is omitted, provision is still afforded by the gripping members G and H for accommodating conductors of different dimensions, because as shown the curved gripping portions Z of the members are of suflicient radial curvature to take both large and small conductors within certain limits.

In the modifications shown in Figs. 3 and 4, the construction of tie rods S and grip ping devices G and H is the same as in Figs. 1 and 2, but the clamping members are divided and constructed in two portions F, which encircle the insulators and are clamped thereto as by means of the bolts a.

In Fig. 5 a construction similar to Figs. 3 and 4 is shown, except that the tie rods S are provided with turn buckles S The ends of the tie rods S in this instance are provided with eyes T secured over the lugs U as by means of the nuts U In Fig. 7 another. modification is shown applicable to a slightly difi'erent form of insulator A in which the distance between the bottom of the groove 6 in the top of the insulator and the center line of the groove 0 in the side of the insulator is very short, so that difficulty would be experienced in fitting gripping devices like those shown in Fig. 1, for instance, to the conductor. In a construction like that shown in Fig. 7, the lugs d of the clamping member 6 are preferably bent at an angle as shown, and provided with the slots f to take the bolt 9 forming the pivot pin for the gripping member h. The gripping member or jaw j is suitably secured to the gri ping member 72. as by means of the bolts By this conthe conductor the insulator.

I claim and desire to obtain by Letters Patent the following:

1. A clamping set for clamping a conductor to insulators, comprising two insulators, clamping means for each insulator, conductor gripping devices carried by the said clamping means, tie members connecting said clamping means, and means for adjusting said tie members in accordance with the distance between the axes of said insulators. I

2. A clamping set for clamping a conductor to insulators, comprising two insulators, clamping means for each insulator, conductor gripping devices carried by said clamping means, tie members connecting said clamping means at each side, means for adjusting said tie members longitudi-- nally to accommodate different distances between the centers of the insulators, and means for preventing transverse twisting of the insulators and clamping means.

3. A clamping set for clamping a conductor to insulators, comprising two insulators arranged side by side, clamping means embracing each insulator, conductor gripping devices carried by the said clamping means, projections at each side of the clamping means, and adjustable tie rods connecting the said projections at each side of the clamping means.

4. A clamping set for clamping a conductor to insulators, comprising two insulators arranged side by side, clamps partially encircling the outside of each insu- EDWIN G. HATCH.

Witnesses:

WALTER S. J come, A. C. PARHAM.

Copies of this patent may be obtained for five cents each, by addressing! the Commissioner 0! Patents.

Washington, D. O. 

